Electric glow discharge tube



Aug. 27, 1940. v LEDERER 2, 8 ELECTRIC GLOW DISCHARGQ TUBE Original Filed July 18, 1930 INvEA/TBfl ANTON LEDERGEJ 2 1,3 ATTMEYS QM W Patented Aug. 27, 1940 UNITED STATES PATENT OFFICE ELECTRIC GLOW DISCHARGE TUBE Anton Lederer, Vienna, Austria Catherine 4 Danzer and General Conrad Randa, executors of saidv Anton Lederer, deceased, assignors, by mesne assignments, to General Electric Company, a corporation of New York Application July 18, 1930, Serial No. 468,884. Re-

newed October 20, 1939. In

Austria July 30,

8 Claims. (01. 176-122) Inasmuch as the lighting effect of such. tubes is dependent upon the distribution of the light intensity within it, the problem was to build the tubes in such a way that as far as possible their whole and the biggest possible space selected, contributed to the lighting effect, that is to say, that there were no parts where none or hardly any lighting efiect is noticeable and that on the other hand allpossibilities of the discharge are made use of.

Experiments have shown, and this forms the abject of the present invention, that the full lighting of such tubes is dependent upon the proper mutual distance and on the arrangement of the electrodes, and on the shape and dimensions of the glass bulb. However, all these con- .ditions must be considered simultaneously in order to obtain a lighting effect from the whole and the biggest possible gas-filled space.

Experimentshave shown that for a rare gas tube having a globe-shaped-or similar bulb and a symmetrical arrangement of the electrodes (the electrodes lying on a middle plane at equal distance from the centre of the globe) the diameter of the globe should have a length of about three times the distance between the electrodes. The possible electrode distance depends upon the nature of the tube; it may be about 50 mm. and

in this case the globe shaped bulb should havea diameter of neither more or less than about 150 mm.

The light phenomena are in their distribution dependent also upon the shape of the tube so i that when a cylindrical bulb is used all other relevant conditions must be suited to it. As a matter of course, inall cases, an electrode distance should be the basis which is possible-under the given conditions.

The enclosed drawing shows the light phenomenon of a tube for alternating current made according to the present invention.

The two electrodes 0 are arranged on supports and are connected to the leading-in wires. If the electrodes are sufliciently heated an arc is formed. The pressure of the rare gas and the inter-electrode spacing are mutually small enough to provide illumination by expanded cathodic light whilst the positive column is effectively predominated or even suppressed.

The stem m carries the two electrodes. Spirals passing through the electrodes 0 and connected to said electrodes at one end have their other ends transversally connected by means of a conducting bridge I as shown. By passing current through said spirals and heating the electrodes the gas or gases contained in the tube is or are ionised, and an arc is formed; and further,

aroundeach of the electrodes there develops an aureole a and al of intensely luminescent gas whereas the surrounding space up to the dotted I line r is filled by gases of less luminosity.

The glass bulb b is according to the present invention selected in such a way that it substantially encloses the whole light phenomenon.

As a matter of course, and as described, there should be in order to obtain the beautiful light effect, at least one electrode which by the action of heat can emit electrons and cause the formation of an arc.

I claim as my invention:

1. An electric illuminating lamp comprising a bulb, two closely spaced electrodes therein at least one of which is capable of emitting electrons freely when heated, the diameter of the bulb being approximately three times the distance between the electrodes, a resistance member capable of heating said electrode to its electron emitting temperature, one end of which resistance member is connected to the electron emitting electrode and the other end thereof to the other electrode to permit the application of a poten-- tial between said electrodes, and a rare gas filling or said lamp. I

2. An electric illuminating lamp for alternat-' ing current, comprising a bulb, a rare gas filling,

.two tubular electrodes of small diameter each being connected together ing current, comprising a globular bulb, two'co-.

operating electrodes thereinlocated about 50 mm.

apart substantially centrally therein, each of which electrodes is capable of emitting electrons freely at relatively low temperature, members for indirectly heating said electrodes, lamp terminals permitting electric current to be supplied to said heating members and a potential to be applied between the electrodes, and a rare gas filling for said lamp, said lamp bulb having a diameter of about mm.

4. An electric illuminating lamp comprising a bulb, co-operating electrodes therein at least one of which is capable of emitting electrons freely at relatively low temperature, the diameter of the bulb being approximately three times the distance between the electrodes, a resistance heater for indirectly heating said electrode, lamp terminals permitting electric current to be supplied to said heating member and a potential to be applied between the electrodes, one end of said heater being connected to said emitting electrode and the other end to the other electrode, and a rare gas filling for said lamp.

5. An electric illuminating lamp for alternating current comprising a bulb, two co-operating electrodes therein each of which is capable of emitting electrons freely at'relatively low temperature, the diameter of the bulb being approximately three times the distance between the electrodes, a resistance heater for indirectly heating each electrode, one end of each resistance heater being connected to its electrode, a low resistance bridge connecting the other ends of said resistance heaters, lamp terminals permitting electric current to be supplied to said heating member and a potential to be applied between the electrodes, and a rare gas filling for said lamp.

6. An electric illuminating lamp for alternating current comprising a globular bulb; two tubular co-operating electrodes located centrally therein parallel with one another, the diameter of the bulb being approximately three times the distance between the electrodes, each of which electrodes is capable of emitting electrons freely at relatively low temperature, a resistance member for indirectly heating each electrode, lamp terminals permitting electric current to be supplied to said heating members and a potential to be applied between the electrodes, and a rare gas filling for said lamp.

7. An electric illuminating lamp comprising a bulb, co-operating electrodes therein at least one of which is capable of emitting electrons freely at relatively low temperature, a resistance heater for continuously and indirectly heating said electrode, lamp terminals permitting electric current to be supplied to said heating member and a potential to be applied between the electrodes, one end of said heater being permanently connected to said emitting electrode and the other end thereof being permanently connected to the other electrode, and rare gas filling for said lamp, the size and shape of said lamp bulb being such that its inner wall surface is not nearer said electrode than approximately the perceptible natural boundary of its cathodic light.

8. An electric illuminating lamp for alternating current comprising a globular bulb, two tubular co-operating electrodes located centrally therein parallel with one another, each of which electrodes is capable of emitting electrons freely at relatively low temperature, a resistance member for indirectly heating each electrode, lamp terminals permitting electric current to be supplied to said heating members and a potential to be applied between the electrodes, and a rare gas filling for said lamp, the pressure of said filling and the electrode separation being such that at the electron emitting temperature of said electrodes and with an interelectrode potential approximately of the order of the ionizing poten tial of the rare gas no appreciable positive column can arise, and the size and shape of said lamp being such that its inner wall surface is not nearer either electrode than approximately the perceptible natural boundary of its cathodic light.

ANTON LEDERER. 

